Drawer oven



May 22, 1934. c. A. BARNETT ET AL DRAWER OVEN Filed June 27. 1931 INVENTORS.

Patented May 22, 1934 UNETE ST TEZS PATENT 1,959,518 FiC DRAWER, OVEN Application June 27, 1931, Serial No. 547,260

Claims.

This invention relates to a structure containing a number of superimposed drawers of such size as not to be easily manipulable by hand and, more particularly, it relates to ovens used for the 5 baking or heat treating of cores and molds of the type in which the work is placed in drawers. 7 In installations to be found in foundries for the preparation of cores, molds, and similar articles requiring heat treatment, the large size of the drawers for holding the work has resulted in the provision of mechanical means for moving these drawers in and out of the heating chambers of the oven when work is being put in or taken out. Such means must be capable of supporting the weight of the outer end of a relatively long drawer while the other end is customarily supported on rollers within the oven proper. The means must also be adapted to support the drawer in the withdrawn position while work is being transferred and it must also be possible to withdraw a selected drawer while leaving the others in place, since adjacent drawers cannot be leaded or unloaded at the same time and since, also, it is not alwaysdesirable to fill or empty the entire capacity of the oven at one time. It will be necessary in such cases that one or more drawers be withdrawn from the oven while the others are left therein.

It is, accordingly, an object of the invention to provide means for operating superimposed drawers selectively and with small expenditure of manual effort. Another object of the invention is to provide means for securely engaging drawers to be operated, while at the same time drawers which are not to be operated are left in position. A further object of the invention is to provide drawer engaging means which may be locked in whatever position may be desired.

To the accomplishment of the foregoing and related end, said invention, then, consists of the means and method hereinafter fully described and particularly pointed out in the claims; the annexed drawing and the following description setting forth in detail certain means and one mode of carrying out the invention.

In said annexed drawing:

Fig. 1 is aside elevation of a drawer oven showing the new operating means in place; Fig. 2 is a side elevation showing the operating means for one drawer in the disengaged position; Fig. 3 is a similar view of the operating means in the engaged position; Fig. 4 is a front elevation of the mechanism shown in Fig. 2; Fig. 5 is an enlarged section through a cam constituting an element of the invention; and Fig. 6 is a side elevation of the cam.

While the drawing illustrates the invention as applied to an oven, it will be realized from the following description that the mechanism is clearly applicable to all structure involving a I front of the oven and has an overhanging portion bearing rails 10 forming a track for the trolley 11. From this trolley is suspended a supporting frame comprising a pair of vertical beams 12 to which are attached the various operating means for engaging the drawer fronts, as hereinafter described.

Referring again to the body of the oven, this may be constructed of brick, steel panels, or may be of built-up construction as indicated by the conditions under which the oven is to be used. The oven body contains various heating means, the detail of which does not concern the present invention and need not be further described. A series of superimposed drawers 13, in which the cores, molds, or other work are to be placed, enter the body of the oven and are supported in the rear by rollers or wheels running on trackways in accordance with the construction usual in this type of oven and not shown herein. These drawers are long, heavy and unwieldly and are noteasily operated without mechanical aids, nor can they be maintained in a withdrawn position without a support for the outer end while work is being placed in them or taken out. To overcome this difiiculty and to operate the drawers with a minimum of effort and inconvenience, the lift member 12 carrying a series of drawer-engaging means and supported and moved by the trolley 11 has been used. The present invention v relates particularly to the means.

Referring more particularly to Figs. 2' and 4 of the drawing, the drawer-engaging means comprises a pair of lift fingers 14 fast upon either end of a horizontal cross rod 16, the rod 16 being rotatably mounted in the vertical beams 12. The forward end 22 of each finger is heavier than the rear end so that the forward ends tend to assume the downward position shown in Fig. 2. On the upper surface of the forward end a notch 22' is formed between two upstanding lugs to en'- gage a drawer handle 15 when the parts are in the position of Fig. 3. The lift finger 14 has a rearward extension 14' bearing against the under side of a cam surface 20 in a cam 17. A cam 17 is fast to each end of another cross rod 18 carriedin bearings 18'. on the front faces of the vertical beams 12, the cross rod 18 being drawer-engaging somewhat above the cross rod 16. This arrangement of having the oppositepairs of cams and their corresponding opposite pairs of lifting fingers each fast to a cross shaft automaticallyequalizes the lift on both sides of the drawer front,

thereby avoiding uneven strains upon or distortion of the drawer. An operating handle 19 is provided fast to the cross rod 18. On successive cross rods these handles 19 are staggered as shown in Fig. 4, so that any upper handle may be lowered without striking the handle below. The cam 1'7 comprises a central portion 17, shown in cross section in Fig. 5, having a lower track 20 which increases rapidly in radius as the cam is turned clockwise as seen in Fig. 5, and upper track 21 approximately circular and concentric, with cut notches 26 and 26' ateither end. The cam includes side flanges 2'7, best seen in Fig. 4, which serve to prevent side displacement of the elements which engaged the respective cam tracks.

The inner surface of each cam carries two lugs or limit stops 30 and 31 which stop against the front plates of the bearings 18' in the two extreme positionson the cam, thus preventing overtravel. It willbe seen that the rear extensions l4"of the fingers 14 are constantly in engagement with the cam 20 so that movement of the handle 19 from the position of Fig. 2 to that of Fig. 3 depresses the end of the fingers, thus supporting the weight of the front of the drawer 13 on the two fingers. The notch 22' catching the edge of the handle transmits pushing and pulling motions to the drawer, when the entire frame system 12 etc., is pulled out on the trolley 11.

To hold the handles 19 in their upper position when the lifting elements are idle and to lock the cams in position and thus to lock the fingers 14 in engagement with the drawer handles when the lifting device is in use, as in Fig. 3, a latch 23 is pivoted as at 24 above each cam on one side beam 12 only. These latches are weighted at their outer ends as at 23 and thus always tend downward by gravity, riding on the cam track 21. A double nosed lug 25 is formed on the lower ridge of the latch 23 so that one nose or other of the lug 25 engages in the notch 26 or 26 according to the position of the lug 17, as will be apparent from Figs. 2, 3 and 5. It will be apparent that in either position, the handle 19 must be moved sufficiently to free the lug 25 from its notch before any movement either to release orengage the finger 14 from the drawer handle 15 can be made.

The above described withdrawing means is useful in the operation of all apparatus having a plurality of superimposed drawers and provides a means by which drawers may be withdrawn selectively, effectively, and securely. The long arm of the handles 19 combined with the short arm of either end of the fingers 14 gives a mechanical advantage sufficient to enable a workman to use the device with the largest and heaviest drawers encountered in practice, while the locking devices prevent accidental release of the front of any drawer when pulled out.

other means than those shown and that what we have described is illustrative rather than limiting. The scope of the invention is to be ascertained from the following claims.

' What we claim is:

1. In a drawer oven, a trolley and a supporting frame carried thereby, the combination of means on said supporting frame adapted to engage and slightly lift said drawers, each of said means comprising a cam, an actuating lever directly connected to said cam, a lift finger pivoted to said supporting frame and operated by said cam, handles on said drawers adapted to be engaged by said lift finger, a latch adapted for looking engagement with said cam, and fianges on said cam guiding said finger and said latch.

2. In an oven having drawers adapted to be operated on a trolley through a supporting frame, the combination of means on said supporting frame adapted to engage said drawers, comprising for each drawer a lift finger, alatch and a cam, a handle rigidly connected with said cam, said cam having notches adapted to engage said latch, to lock said lift finger in engagement with said drawers, or out of position for engagement with said drawers, and at the same time to lock said handle in position, stops on said cam engageable with said frame to prevent overtravel of the cam.

3. In a device of the character described, including a plurality of superimposed drawers, handles on said drawers, a frame adapted to support the forward ends of said drawers, the combination of means on said frame adapted to engage said handles individually, said engaging means comprising for each drawer a lift finger, a latch, a lug on said latch, and a cam on which one end of said lift finger rides, said cam having a notch adapted to engage said lug to lock said lift finger in engagement with said handle, a cam actuating lever, and said cam having another notch adapted to engage said lug on said pawl to lock said cam actuating lever in upright position.

' 4. In a core and mold oven having a plurality of superimposed drawers, widely spaced handles on the front of each drawer, a trolley trackway extending longitudinally above the paths of said drawers, a trolley on the trackway, a supporting frame dependent from said trolley, said frame being of substantial width, the combination of sets of means, one set for each drawer, supported on said frame, each set comprising a pair of fingers adapted to engage said handles to lift and pull the drawer, a cross rod having one such fin- I ger on each end, hearings on said frame supporting said rod, another cross rod, bearings on said frame supporting said second cross rod, a cam on each end of said second rod, each of said fingers bearing on one of said cams, an actuating lever on said cam rod, and latching means for holding the set in and out of engaging position, said cams constituting an element of said latching means.

5. In an oven having a plurality of superimposed drawers and a withdrawing device on a support, the combination of a series of lift fingers in rigidly connected pairs attached to said withdrawing device and each pair adapted to engage one of said drawers at transversely disposed points, a series of cams rigidly connected in pairs, one pair for each drawer, and engaging said lift fingers, one cam of each pair having two notches therein, and a latch lever for each notched cam having lugs adapted to enter said notches.

CHARLES A. BARNETT. HARRY W. STEINDORF. 

